Method of treating proppants and fractures in-situ with fluorinated silane

ABSTRACT

Method of treating proppant particles present in a fractured subterranean geological formation comprising hydrocarbons in-situ with fluorinated silane.

BACKGROUND

Oil and natural gas can be produced from wells having porous andpermeable subterranean formations. The porosity of the formation permitsthe formation to store oil and gas, and the permeability of theformation permits the oil or gas fluid to move through the formation.Permeability of the formation is essential to permit oil and gas to flowto a location where it can be pumped from the well. Sometimes thepermeability of the formation holding the gas or oil is insufficient forthe desired recovery of oil and gas. In other cases, during operation ofthe well, the permeability of the formation drops to the extent thatfurther recovery becomes uneconomical. In such cases, it is common tofracture the formation and prop the fracture in an open condition usinga proppant material or propping agent. Such fracturing is usuallyaccomplished by hydraulic pressure. The proppant material or proppingagent is typically a particulate material, such as sand and (man-made)engineered proppants, such as resin coated sand and high-strengthceramic materials (e.g., sintered bauxite, crystalline ceramic bubbles,and ceramic (e.g., glass) beads), which are carried into the fracture bya fluid.

Further, for example, if relatively light weight, porous crystallineceramic (e.g., alumina) proppants are used, fluid (e.g., the fracturingfluid) can penetrate into the proppant increasing its density, which canin turn can adversely affect the flow of the proppant into the fracturedareas.

There continues to be a need for additional proppant options,preferably, proppants with improved properties. Also, for example, thereis a desire, particularly for relatively light weight, porous proppants,to prevent, or at least reduce, penetration of fluids into theproppants.

SUMMARY

In one aspect, the present disclosure provides a method of treatingproppant particles present in a fractured subterranean geologicalformation comprising hydrocarbons, the method comprising injectingfluorinated silane into the fracture to treat the proppant particlesin-situ. In some embodiments, the resulting fluorinated siloxane isbonded to the treated particle.

In another aspect, the present disclosure provides a method offracturing a subterranean geological formation comprising hydrocarbons,the method comprising:

injecting a hydraulic fluid into a subterranean geological formationcomprising hydrocarbons at a rate and pressure sufficient to open afracture therein;

injecting into a fracture fluid comprising a plurality of proppantparticles; and

subsequent to the injection of the hydraulic and fracture fluids,injecting fluorinated silane into the fracture to treat the proppantparticles in-situ.

In another aspect, the present disclosure provides a method offracturing a subterranean geological formation comprising hydrocarbons,the method comprising:

injecting a hydraulic fluid into a subterranean geological formationcomprising hydrocarbons at a rate and pressure sufficient to open afracture therein; and

injecting fluorinated silane into the fracture to treat the fracturein-situ. In some embodiments, and typically, prior to injecting thefluorinated silane into the fracture, the method further comprisesinjecting into a fracture fluid comprising a plurality of proppantparticles into the fracture. In some embodiments, subsequent toinjecting the fluorinated silane into the fracture, the method furthercomprises injecting into a fracture fluid comprising a plurality ofproppant particles into the fracture. In some embodiments, at least someof the proppant injected into the fracture is treated with thefluorinated silane prior to their injection.

In some embodiments, the fluorinated silane comprises a reactivefluorinated silane selected from the group consisting of:

Rf{-Q-[SiY_(3-x)(R)_(x)]_(y)}_(z);

a polymeric fluorinated composition comprising:

-   -   at least one divalent unit represented by the formula:

-   -    and    -   at least one of        -   at least one divalent unit represented by the formula:

-   -    or        -   a chain-terminating group represented by the formula:

—S—W—SiY_(3-x)(R)_(x); and

a fluorinated urethane oligomer of at least two repeat units comprising:

-   -   at least one end group represented by the formula —O—Z—Rf², and    -   at least one end group represented by the formula        —X¹—W—SiY_(3-x)(R)_(x);        wherein

Rf is a monovalent or multivalent perfluoroalkyl group optionallyinterrupted by at least one —O—;

Rf² is a monovalent perfluoroalkyl group optionally interrupted by atleast one —O—;

each R is independently selected from the group consisting of alkylhaving one to six carbon atoms and aryl;

Q is a divalent or trivalent organic linking group;

each Y is independently selected from the group consisting of hydroxyl,alkoxy, acyloxy, and halogen;

each R¹ is independently selected from the group consisting of hydrogenand alkyl having one to four carbon atoms;

each W is independently selected from the group consisting of alkylene,arylalkylene, and arylene, wherein alkylene is optionally interrupted orsubstituted by at least one heteroatom;

each X is independently selected from the group consisting of —NH—, —O—,and —S—;

X¹ is selected from the group consisting of —N(R³)—, —S—, —O—,—O—C(O)—NH—, and —O-alkylene-O—C(O)—NH—;

Z is a divalent organic linking group;

x is 0, 1, or 2;

y is 1 or 2; and

z is 1, 2, 3, or 4.

In some embodiments, the fluorinated silane comprises at least onefluorinated urethane oligomer of at least two repeat units comprising:

-   -   at least one end group represented by the formula

—O—(CH₂)_(n)N(R⁴)S(O)₂—Rf³, and

-   -   at least one end group represented by the formula

—NH—(CH₂)_(n)—SiY₃;

wherein

R⁴ is alkyl having one to four carbon atoms

Rf³ is a perfluoroalkyl group having from one to eight carbon atoms;

each Y is independently selected from the group consisting of hydroxyl,alkoxy, acyloxy, and halogen; and

each n is independently an integer from 1 to 4.

In some embodiments, the fracture has a conductivity improved by thepresence of the (resulting) fluorinated siloxane. The conductivity of afracture is a measure of the effectiveness of a hydraulically treatedfracture or essentially how well the fracture improves the flow of oilor gas from the formation. The conductivity of a fracture can bedetermined using API Conductivity Test RP 61, entitled “RecommendedPractices for Evaluating Short Term Proppant Pack Conductivity”(October, 1989).

Treated proppants and/or fractures described herein are useful, forexample, in facilitating the removal of fracturing fluids that have beeninjected into subterranean formation, including increasing the removalrate of the fracturing fluid. While not wanting to be bound by theory,it is believed this enhanced back-production of the fracturing fluids isdue to the fluorinated siloxane altering the wettability of the proppantand/or fracture, thus rendering the proppant and/or fracturehydrophobic, oleophobic, and non-wetted by the fracturing fluids. Anadditional advantage of enhancing the fluid production from the fracturecomprising the proppant and/or fracture treated with the fluorinatedsilane is thought to be the reduction in turbulent flow that shouldsignificantly reduce non-Darcy effects. Non-Darcy effects caneffectively reduce the conductivity of a fracture by reducing fluidproduction. Advantages of embodiments of treated particles having aplurality of pores is that the treated particle has at least one ofwater or oil imbibition up to 95% as compared to a comparable, untreatedparticle.

DETAILED DESCRIPTION

Exemplary proppants for practicing the methods described herein includethose known in the art for use in fractured subterranean geologicalformations comprising hydrocarbons, including engineered proppants(e.g., resin coated sand, sintered bauxite, crystalline ceramic bubbles,and ceramic (e.g., glass) beads), as well as sand graded to desiredindustry standards). The term “ceramic” as used herein refers toglasses, crystalline ceramics, glass-ceramics, and combinations thereof.Suitable proppant can be made by techniques known in the art and/orobtained from commercial sources. Exemplary proppants include those madeof a material selected from the group consisting of sand, thermoplastic,clay, glass, and alumina (e.g., sintered bauxite). Examples of proppantsinclude sand, clay-based particles, thermoplastic particles, andsintered bauxite particles. Sand proppants are available, for example,from Badger Mining Corp., Berlin, Wis.; Borden Chemical, Columbus, Ohio;Fairmont Minerals, Chardon, Ohio. Thermoplastic proppants are available,for example, from the Dow Chemical Company, Midland, Mich.; and BJServices, Houston, Tex. Clay-based proppants are available, for example,from CarboCeramics, Irving, Tex.; and Saint-Gobain, Courbevoie, France.Sintered bauxite ceramic proppants are available, for example, fromBorovichi Refractories, Borovichi, Russia; 3M Company, St. Paul, Minn.;CarboCeramics, and Saint Gobain. Engineered proppants such as glass beadand ceramic microsphere proppants are available, for example, fromDiversified Industries, Sidney, British Columbia, Canada; and 3MCompany.

In some embodiments, the proppant is at least 100 micrometers (in someembodiments, at least 200, 300, 400, 500, 600, 700, 800, 900, 1000,1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2500, oreven at least 3000 micrometers; in some embodiments, in a range from 500micrometers to 1700 micrometers) in size. In some embodiments, theproppant have particle sizes in a range from 100 micrometers to 3000micrometers (i.e., about 140 mesh to about 5 mesh) (in some embodiments,in a range from 1000 micrometers to 3000 micrometers, 1000 micrometersto 2000 micrometers, 1000 micrometers to 1700 micrometers (i.e., about18 mesh to about 12 mesh), 850 micrometers to 1700 micrometers (i.e.,about 20 mesh to about 12 mesh), 850 micrometers to 1200 micrometers(i.e., about 20 mesh to about 16 mesh), 600 micrometers to 1200micrometers (i.e., about 30 mesh to about 16 mesh), 425 micrometers to850 micrometers (i.e., about 40 to about 20 mesh), 300 micrometers to600 micrometers (i.e., about 50 mesh to about 30 mesh), 250 micrometersto 425 micrometers (i.e., about 60 mesh to about 40 mesh), 200micrometers to 425 micrometers (i.e., about 70 mesh to about 40 mesh),or 100 micrometers to 200 micrometers (i.e., about 140 mesh to about 70mesh).

In some embodiments, the proppants (e.g., ceramic particles) have aplurality of pores. The pores can be closed or open with respect to eachother, or a mixture of opened and closed porosity. In some embodiments,the proppants (e.g., ceramic particles) have a density of at least 2g/cm³ (in some embodiments, at least 2.5 g/cm³, at least 3 g/cm³; insome embodiments, in a range from 2 g/cm³ to 3 g/cm³).

In some embodiments, the fluorinated silane comprises a reactivefluorinated silane represented by the formula (I):

Rf{-Q-[SiY_(3-x)(R)_(x)]_(y)}_(z)  I,

-   -   wherein Rf, Q, Y, R, x, y, and z are as defined above. Rf is a        monovalent or multivalent perfluoroalkyl group optionally        interrupted by at least one —O—. Rf can be a linear, branched,        and/or cyclic structure, that may be saturated or unsaturated.        The term “perfluoroalkyl group” includes groups in which all C—H        bonds are replaced by C—F bonds as well as groups in which        hydrogen or chlorine atoms are present instead of fluorine atoms        provided that not more than one atom of either hydrogen or        chlorine is present for every two carbon atoms. In some        embodiments, when hydrogen and/or chlorine are present, Rf        includes at least one trifluoromethyl group.

In some embodiments, Rf is a monovalent perfluoroalkyl group of formula(C_(n)F_(2n+1)), wherein n is an integer from 1 to 20 (in someembodiments, from 3 to 12 or even from 3 to 8). In some embodiments, Rfis C₄F₉.

In some embodiments, Rf is a perfluoropolyether group having two or morein-chain oxygen atoms. In some embodiments, the perfluoropolyether groupcomprises perfluorinated repeating units selected from the groupconsisting of —(C_(n)F_(2n))—, —(C_(n)F_(2n)O)—, —(CF(Rf⁴))—,—(CF(Rf⁴)O)—, —(CF(Rf⁴)C_(n)F_(2n)O)—, —(C_(n)F_(2n)CF(Rf⁴)O)—,—(CF₂CF(Rf⁴)O)—, and combinations thereof (in some embodiments,—(C_(n)F_(2n)O)—, —(CF(Rf⁴)O)—, —(CF(Rf⁴)C_(n)F_(2n)O)—,—(C_(n)F_(2n)CF(Rf⁴)O)—, —(CF₂CF(Rf⁴)O)—, and combinations thereof);wherein Rf⁴ is a perfluoroalkyl group, a perfluoroalkoxy group, or aperfluoroether group, each of which can be linear, branched, or cyclic,and can have 1 to 9 carbon atoms and up to 4 oxygen atoms; and n is aninteger from 1 to 12 (in some embodiments, from 1 to 6, from 1 to 4, oreven from 1 to 3). The perfluorinated repeating units may be arrangedrandomly, in blocks, or in alternating sequence.

In some embodiments, Rf is a monovalent (i.e., z is 1)perfluoropolyether group. In some of these embodiments, Rf is terminatedwith C_(n)F_(2n+1)—, C_(n)F_(2n+1)O—, or X′C_(n)F_(2n)O—, wherein X′ isa hydrogen or chlorine atom. In some of these embodiments, the terminalgroup is C_(n)F_(2n+1)— or C_(n)F_(2n+1)O—, wherein n is an integer from1 to 6 or from 1 to 3. In some of these embodiments, the approximateaverage structure of Rf is C₃F₇O(CF(CF₃)CF₂O)_(p)CF(CF₃)— orCF₃O(C₂F₄O)_(p)CF₂—, wherein the average value of p is 3 to 50.

In some embodiments, Rf is a divalent (i.e., z is 2) perfluoropolyethergroup. In some of these embodiments, Rf is selected from the groupconsisting of —CF₂O(CF₂O)_(m)(C₂F₄O)_(p)CF₂—,—CF(CF₃)—(OCF₂CF(CF₃))_(p)O—Rf⁵—O(CF(CF₃)CF₂O)_(p)CF(CF₃)—,—CF₂O(C₂F₄O)_(p)CF₂—, and —(CF₂)₃O(C₄F₈O)_(p)(CF₂)₃—, wherein Rf⁵ is adivalent, perfluoroalkylene group containing at least one carbon atomand optionally interrupted in chain by O or N; m is 1 to 50; and p is 3to 40. In some embodiments, Rf⁵ is (C_(n)F_(2n)), wherein n is 2 to 4.In some embodiments, Rf is selected from the group consisting of—CF₂O(CF₂O)_(m)(C₂F₄O)_(p)CF₂—, —CF₂O(C₂F₄O)_(p)CF₂—, andCF(CF₃)—(OCF₂CF(CF₃))_(p)O—(C_(n)F_(2n))—O(CF(CF₃)CF₂O)_(p)CF(CF₃)—,wherein n is 2 to 4, and the average value of m+p or p or p+p,respectively, is from about 4 to about 24. In some embodiments, p and mmay be non-integral.

The divalent or trivalent organic linking group, Q, can be a linear,branched, or cyclic structure, that may be saturated or unsaturated andoptionally contains one or more heteroatoms selected from the groupconsisting of sulfur, oxygen, and nitrogen, and/or optionally containsone or more functional groups selected from the group consisting ofester, amide, sulfonamide, carbonyl, carbonate, urea, and carbamate. Qincludes at least 2 carbon atoms and not more than about 25 carbon atoms(in some embodiments, not more than 24, 23, 22, 21, 20, 19, 18, 17, 16,15, 14, 13, 12, 11, or even not more than 10 carbon atoms). When two,three, or four Q groups are present, each Q is independently selected.In some embodiments, Q is a linear hydrocarbon containing 1 to about 10carbon atoms, optionally containing 1 to 4 heteroatoms and/or 1 to 4functional groups. In some of these embodiments, Q contains onefunctional group.

Exemplary divalent Q groups include —SO₂NR²(CH₂)_(k)O(O)C—,—CON(R²)(CH₂)_(k)O(O)C—, —(CH₂)_(k)O(O)C—, —C(O)N(R²)—(CH₂)_(k)—,—CH₂CH(O-alkyl)CH₂O(O)C—, —(CH₂)_(k)C(O)O(CH₂)_(k)—, —(CH₂)_(k)SC(O)—,—(CH₂)_(k)O(CH₂)_(k)O(O)C—, —(CH₂)_(k)S(CH₂)_(k)O(O)C—,—(CH₂)_(k)SO₂(CH₂)_(k)O(O)C—, —(CH₂)_(k)S(CH₂)_(k)OC(O)—,—(CH₂)_(k)SO₂N(R²)(CH₂)_(k)O(O)C—, —(CH₂)_(k)SO₂—,—SO₂N(R²)(CH₂)_(k)O(CH₂)_(k)—, —SO₂N(R²)(CH₂)_(k)—,—(CH₂)_(k)O(CH₂)_(k)C(O)O(CH₂)_(k)—,—(CH₂)_(k)SO₂N(R²)(CH₂)_(k)C(O)O(CH₂)_(k)—,—(CH₂)_(k)SO₂(CH₂)_(k)C(O)O(CH₂)_(k)—, —CON(R²)(CH₂)_(k)C(O)O(CH₂)_(k)—,—(CH₂)_(k)S(CH₂)_(k)C(O)O(CH₂)_(k)—, —CH₂CH(O-alkyl)CH₂C(O)O(CH₂)_(k)—,—SO₂N(R²)(CH₂)_(k)C(O)O(CH₂)_(k)—, —(CH₂)_(k)O(CH₂)_(k)—,—CH₂O—(CH₂)_(k)—, —OC(O)N(R²)(CH₂)_(k)—, —(CH₂)_(k)N(R²)—,—C_(k)H_(2k)—OC(O)NH—, —(CH₂)_(k)N(R²)C(O)O(CH₂)_(k)—, —(CH₂)_(k)—,—C_(k)H_(2k)—, —C(O)S—(CH₂)_(k)—, and —CH₂OC(O)N(R²)—(CH₂)_(k)—, whereinR² is hydrogen, C₁₋₄ alkyl, or phenyl; and k is 2 to about 25 (in someembodiments, 2 to 15 or even 2 to 10).

Exemplary trivalent Q groups include

wherein R² is hydrogen,

-   -   C₁₋₄ alkyl, or phenyl; each n and m are independently integers        from 1 to 20 (in some embodiments, from 1 to 6 or even from 1 to        4); m′ is an integer from 1 to 20 (in some embodiments, from 1        to 10 or even from 1 to 3); Q² is selected from the group        consisting of —C(O)NH—(CH₂)_(n′)— and —(CH₂)_(n′)—, wherein n′        is an integer from 0 to 4; and X is selected from the group        consisting of —NH—, —O—, and —S—.

Each Y in Formula I is selected from the group consisting of hydroxyl,alkoxy (e.g., of 1 to 4 or even 1 to 2 carbon atoms), aryloxy (e.g.,phenoxy), acyloxy (e.g., of 1 to 4 or even 1 to 2 carbon atoms),polyalkyleneoxy, and halogen (e.g., Cl or Br). “Polyalkyleneoxy” refersto —O—(CHR⁵—CH₂O)_(q)—R³ wherein R³ is C₁₋₄ alkyl, R⁵ is hydrogen ormethyl, with at least 70% of R⁵ being hydrogen, and q is 1 to 40, oreven 2 to 10. In some embodiments, each Y is independently ahydrolyzable group selected from the group consisting of alkoxy (e.g.,of 1 to 4 or even 1 to 2 carbon atoms), aryloxy (e.g., phenoxy), andhalogen (e.g., Cl or Br). These hydrolysable groups are capable ofhydrolyzing, for example, in the presence of water, optionally underacidic or basic conditions, producing groups capable of undergoing acondensation reaction, for example silanol groups. In some embodiments,R is alkyl of one to six carbon atoms (e.g., methyl, ethyl, propyl,isopropyl, butyl, isobutyl). In some embodiments, R is aryl (e.g.,phenyl). In some embodiments, x is 0. In some embodiments, x is 1.

Some reactive fluorinated silanes of formula I are commerciallyavailable, for example, a fluorinated silane (available, for example,from Daikin Industries, Inc., New York, N.Y. under the trade designation“OPTOOL DSX”) and tridecafluorooctyl functional silanes (available, forexample, from United Chemical Technologies, Inc., Bristol, Pa. under thetrade designation “PETRARCH” (e.g., grades “T2492” and “T2494”).

The compounds of formula I described above can be synthesized usingconventional synthetic methods. For example, when Rf is aperfluoropolyether group, perfluoropolyether esters or functionalderivatives thereof can be combined with a functionalized alkoxysilane,such as a 3-aminopropylalkoxysilane, according to the method describedin U.S. Pat. No. 3,810,874 (Mitsch et al.). It will be understood thatfunctional groups other than esters may be used with equal facility toincorporate silane groups into a perfluoropolyether. Someperfluoropolyether diesters are commercially available (e.g.,CH₃OC(O)CF₂(OCF₂CF₂)₉₋₁₀(OCF₂)₉₋₁₀CF₂C(O)OCH₃, a perfluoropolyetherdiester available, for example, from Solvay Solexis, Houston, Tex.,under the trade designation “FOMBLIN ZDEAL”). Other perfluoropolyetherdiesters may be prepared, for example, through direct fluorination of ahydrocarbon polyether diester by methods known in the art (see, e.g.,U.S. Pat. Nos. 5,578,278 (Fall et al.) and 5,658,962 (Moore et al.).Perfluoropolyether diesters (and perfluoropolyether monoesters) can alsobe prepared, for example, by oligomerization of hexafluoropropyleneoxide (HFPO) and functionalization of the resulting perfluoropolyethercarbonyl fluoride according to the methods described in U.S. Pat. No.4,647,413 (Savu). An exemplary fluorinated silane of formula I whereinRf is a divalent perfluoropolyether group is(CH₃O)₃Si(CH₂)₃NHCOCF₂(OCF₂CF₂)₉₋₁₀(OCF₂)₉₋₁₀CF₂CONH(CH₂)₃Si(OCH₃)₃.

The above-described polyfluoropolyether silanes typically include adistribution of oligomers and/or polymers, and above structures areapproximate average structures where the approximate average is overthis distribution. These distributions may also containperfluoropolyethers with no silane groups or more than two silanegroups. Typically, distributions containing less than about 10% byweight of compounds without silane groups can be used.

Methods of making fluorinated silanes of the formula I, wherein Rf is amonovalent perfluoroalkyl group, are known in the art (e.g., byalkylation of fluorinated alcohols or sulfonamides withchloroalkyltrialkoxysilanes, or alkylation with allyl chloride followedby hydrosilation with HSiCl₃) (see, e.g., U.S. Pat. No. 5,274,159(Pellerite et al.). Fluorinated silanes represented by the formulas

wherein each Rf is independently C_(p)F_(2p+1), wherein p is 1 to 8 andR², R, m, n, m′, n′, X, and Q² are as defined above, can be prepared,for example, by similar methods (e.g., by alkylation ofRf—S(O)₂—N(R²)—(C_(n+m)H_(2(n+m)))—NH(S(O)₂—Rf orRf—S(O)₂—N(R²)—(C_(n)H_(2n))—CH(OH)—(C_(m)H_(2m))—N(R²)—S(O)₂—Rf),respectively, with chloroalkyltrialkoxysilanes) or by reaction ofRf—S(O)₂—N(R²)—(C_(n)H_(2n))—CH(OH)—(C_(m)H_(2m))—N(R²)—S(O)₂—Rf withisocyanatoalkyltrialkoxysilanes as described in U.S. Pat. App. Pub. No.2006/0147645 (Dams et al.).

Perfluoroalkyl silanes of formula I, wherein Rf is a monovalentperfluoroalkyl group, include, for example, any one or any combinationof the following: C₃F₇CH₂OCH₂CH₂CH₂Si(OCH₃)₃;C₇F₁₅CH₂OCH₂CH₂CH₂Si(OCH₃)₃; C₇F₁₅CH₂OCH₂CH₂CH₂Si(OCH₂CH₃)₃;C₇F₁₅CH₂OCH₂CH₂CH₂Si(CH₃)(OCH₃)₂; C₇F₁₅CH₂OCH₂CH₂CH₂SiCl₃;C₇F₁₅CH₂OCH₂CH₂CH₂Si(CH₃)Cl₂; C₇F₁₅CH₂OCH₂CH₂CH₂SiCl(OCH₃)₂;C₇F₁₅CH₂OCH₂CH₂CH₂SiCl₂(OC₂H₃); C₇F₁₅C(O)NHCH₂CH₂CH₂Si(OCH₃)₃;CF₃(CF₂CF(CF₃))₃CF₂C(O)NHCH₂CH₂CH₂Si(OCH₂CH₃)₃;C₈F₁₇SO₂N(CH₂CH₃)CH₂CH₂CH₂Si(OCH₃)₃;C₈F₁₇SO₂N(CH₂CH₃)CH₂CH₂CH₂Si(OCH₂CH₃)₃; C₄F₉SO₂N(CH₃)CH₂CH₂CH₂Si(OCH₃)₃;C₄F₉SO₂N(CH₃)CH₂CH₂CH₂Si(OCH₂CH₃)₃; C₈F₁₇CH₂CH₂Si(OCH₃)₃;C₆F₁₃CH₂CH₂Si(OCH₂CH₃)₃; C₆F₁₃CH₂CH₂Si(Cl)₃; C₈F₁₇CH₂CH₂Si(OCH₂CH₃)₃;C₈F₁₇SO₂N(CH₂CH₃)CH₂CH₂CH₂SiCl₃; C₈F₁₇SO₂N(CH₃)CH₂CH₂CH₂Si(CH₃)Cl₂;C₈F₁₇CH₂OCH₂CH₂CH₂Si(OAc)₃; [C₄F₉S(O)₂N(CH₃)CH₂]₂CHOCH₂CH₂CH₂Si(OCH₃)₃;[C₄F₉S(O)₂N(CH₃)CH₂]₂CHOC(O)NHCH₂CH₂CH₂Si(OCH₃)₃, andC₄F₉S(O)₂N(CH₃)CH₂CH₂CH₂N(S(O)₂C₄F₉)CH₂CH₂CH₂Si(OCH₃)₃. Suitablefluorinated silanes of formula I include a mixture of isomers (e.g., amixture of compounds containing linear and branched perfluoroalkylgroups).

In some embodiments, useful fluorinated siloxanes comprise acondensation product of a polymeric fluorinated composition comprising:

-   -   at least one divalent unit represented by the formula (II):

-   -    and    -   at least one of        -   at least one divalent unit represented by the formula (III):

-   -    or        -   a chain-terminating group represented by the formula (IV):

—S—W—SiY_(3-x)(R)_(x)  IV,

wherein, Rf², R¹, R, W, X, Y, Z, and x are as defined above.

The term “polymeric” refers to both oligomers and polymers. In someembodiments, the number of units represented by formula II is in a rangefrom 1 to 100 (in some embodiments from 1 to 20). In some embodiments,the units represented by formula II are present in a range from 40% byweight to 80% by weight (or even from 50% to 75% by weight) based on thetotal weight of the polymeric fluorinated composition. In someembodiments, the number of units represented by formula III is in arange from 0 to 100 (or even from 0 to 20). In some embodiments, theunits represented by formula III are present in a range from 1% to 20%by weight (or even 2% to 15% by weight) based on the total weight of thepolymeric fluorinated composition. In some embodiments, the polymericfluorinated composition contains at least 5 mole % (based on total molesof monomers) of Y groups. In some embodiments, the polymeric fluorinatedcomposition has a number average molecular weight in a range from 400 to100000, from 3500 to 100000, or even from 10000 to 75000 grams per moleor in a range from 600 to 20000, or even from 1000 to 10000 grams permole. It will be appreciated by one skilled in the art that usefulpolymeric fluorinated compositions exist as a mixture of compounds.

A divalent unit of formula II is typically introduced into a polymericfluorinated composition by polymerizing a monomer of the formula (IIa):

Fluorochemical monomers of formula IIa and methods for the preparationthereof are known in the art (see, e.g., U.S. Pat. No. 2,803,615(Ahlbrecht et al.). Examples of such compounds include, for example,acrylates or methacrylates derived from fluorochemical telomer alcohols,acrylates or methacrylates derived from fluorochemical carboxylic acids,perfluoroalkyl acrylates or methacrylates as disclosed in U.S. Pat. No.5,852,148 (Behr et al.), perfluoropolyether acrylates or methacrylatesas described in U.S. Pat. No. 4,085,137 (Mitsch et al.), and fluorinatedacrylamides, methacrylamides, thioacrylates, and meththioacrylates asdescribed in U.S. Pat. No. 6,689,854 (Fan et al.).

In some embodiments of formulas II and IIa, Rf² is a monovalentperfluoroalkyl group described above for Rf in embodiments of a compoundof formula I.

The divalent organic linking group, Z, can be a linear, branched, orcyclic structure, that may be saturated or unsaturated and optionallycontains one or more heteroatoms selected from the group consisting ofsulfur, oxygen, and nitrogen, and/or optionally contains one or morefunctional groups selected from the group consisting of ester, amide,sulfonamide, carbonyl, carbonate, ureylene, and carbamate. Z includes atleast 1 carbon atom and not more than about 25 carbon atoms (in someembodiments, not more than 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14,13, 12, 11, or even not more than 10 carbon atoms). In some embodimentsof formulas II and IIa, Z is a divalent organic linking group asdescribed above for divalent Q groups. In some embodiments of formulasII and IIa, Z is —C_(y)H_(2y)—, —CON(R¹)C_(y)H_(2y)—,—SO₂N(R¹)C_(y)H_(2y)—, or C_(y)H_(2y)SO₂N(R¹)C_(y)H_(2y)—, wherein R¹ ishydrogen, or alkyl of one to four carbon atoms, and y is independentlyan integer from 1 to 6 (in some embodiments from 2 to 4). In someembodiments, R¹ is hydrogen. In some embodiments, R¹ is alkyl of one tofour carbon atoms.

Examples of fluorinated monomers of formula IIa include:C₄F₉SO₂N(CH₃)C₂H₄OC(O)CH═CH₂; C₅F₁₁SO₂N(C₂H₅)C₂H₄OC(O)CH═CH₂;C₆F₁₃SO₂N(C₂H₅)C₂H₄OC(O)C(CH₃)═CH₂; C₃F₇SO₂N(C₄H₉)C₂H₄OC(O)CH═CH₂;C₄F₉CH₂CH₂OC(O)CH═CH₂; C₅F₁₁CH₂OC(O)CH═CH₂; C₆F₁₃CH₂CH₂OC(O)CH═CH₂;CF₃(CF₂)₂CH₂OC(O)CH═CH₂, CF₃(CF₂)₂CH₂OC(O)C(CH₃)═CH₂,CF₃(CF₂)₃CH₂OC(O)C(CH₃)═CH₂, CF₃(CF₂)₃CH₂OC(O)CH═CH₂,CF₃(CF₂)₃S(O)₂N(R^(a))—(CH₂)₂—OC(O)CH═CH₂,CF₃(CF₂)₃S(O)₂N(R^(a))—(CH₂)₂—OC(O)C(CH₃)═CH₂,CF₃CF₂(CF₂CF₂)₂₋₈(CH₂)₂OC(O)CH═CH₂, CF₃(CF₂)₇(CH₂)₂OC(O)C(CH₃)═CH₂,CF₃(CF₂)₇S(O)₂N(R^(a))—(CH₂)₂—OC(O)CH═CH₂,CF₃(CF₂)₇S(O)₂N(R^(a))—(CH₂)₂—OC(O)C(CH₃)═CH₂,CF₃(CF₂)₇CH₂CH₂S(O)₂N(CH₃)—(CH₂)₂—OC(O)C(CH₃)═CH₂,CF₃O(CF₂CF₂)_(u)CH₂OC(O)CH═CH₂, CF₃O(CF₂CF₂)_(u)CH₂OC(O)C(CH₃)═CH₂,C₃F₇O(CF(CF₃)CF₂O)_(u)CF(CF₃)CH₂OC(O)CH═CH₂, andC₃F₇O(CF(CF₃)CF₂O)_(u)CF(CF₃)CH₂OC(O)C(CH₃)═CH₂; wherein R^(a)represents methyl, ethyl or n-butyl, and u is about 1 to 50.

Polymeric fluorinated compositions described herein may have a divalentunit represented by formula III. A divalent unit of formula III istypically introduced into a polymeric fluorinated composition bycopolymerizing a monomer of formula IIa with a monomer of the formula(IIIa):

-   -   wherein R¹, R, W, X, Y, and x are as defined above. In some        embodiments of formula IIIa, the groups R¹, R, Y, and x are        those described above for embodiments of a compound of        formula I. In some embodiments, W is alkylene of one to four        carbon atoms. Some monomers of formula IIIa are commercially        available (e.g., CH₂═C(CH₃)C(O)OCH₂CH₂CH₂Si(OCH₃)₃ (available,        for example, from Union Carbide, New York, N.Y., under the trade        designation “A-174”)); others can be made by conventional        synthetic methods.

Polymeric fluorinated compositions useful in the fracturing methoddescribed herein may optionally include other interpolymerized divalentunits, which may contain hydrophobic, hydrophilic, or water-solubilizinggroups. Useful monomers (including water-solubilizing monomers) that canbe combined with those of formulas IIa and IIIa include non-fluorinatedmonomers described in U.S. Pat. Nos. 6,977,307 (Dams) and 6,689,854 (Fanet. al.).

Useful polymeric fluorinated compositions may have a chain-terminatinggroup represented by formula IV. A chain-terminating group of formula IVmay be incorporated into a polymeric fluorinated composition, forexample, by polymerizing monomers of formula IIa, optionally IIIa, andoptionally at least one non-fluorinated monomer in the presence of achain-transfer agent of the formula (IVa):

HS—W—SiY_(3-x)(R)_(x)  IVa,

wherein R, W, Y, and x are as defined above. In some embodiments offormula IIIa, the groups R, Y, and x are those described above forembodiments of a compound of formula I. In some embodiments, W isalkylene of one to four carbon atoms. Some monomers of formula IVa arecommercially available (e.g., 3-mercaptopropyltrimethoxysilane(available, for example, from Huls America, Inc., Somerset, N.J., underthe trade designation “DYNASYLAN”)); others can be made by conventionalsynthetic methods. A chain-terminating group of formula IV can also beincorporated into a polymeric fluorinated composition by polymerizingmonomers of formula IIa, optionally IIIa, and optionally at least onenon-fluorinated monomer in the presence of a hydroxyl-functionalchain-transfer agent (e.g., 2-mercaptoethanol, 3-mercapto-2-butanol,3-mercapto-2-propanol, 3-mercapto-1-propanol,3-mercapto-1,2-propanediol) and subsequent reaction of the hydroxylfunctional group with, for example, a chloroalkyltrialkoxysilane. In apolymerization reaction to make a polymeric fluorinated composition, asingle chain transfer agent or a mixture of different chain transferagents may be used to control the number of polymerized monomer units inthe polymer and to obtain the desired molecular weight of the polymericfluorochemical silane.

The polymeric fluorinated oligomeric composition can conveniently beprepared through a free radical polymerization of a fluorinated monomerwith optionally a non-fluorinated monomer (e.g., a water-solubilizingmonomer) and at least one of a monomer containing a silyl group or achain transfer agent containing a silyl group using methods known in theart. See, for example, the methods described in U.S. Pat. Nos. 6,977,307(Dams) and 6,689,854 (Fan et. al.).

In some embodiments, the fluorinated silane comprises at least onefluorinated urethane oligomer of at least two repeat units (e.g., from 2to 20 repeating units) comprising at least one end group represented bythe formula —O—Z—Rf², and at least one end group represented by theformula —X¹—W—SiY_(3-x)(R)_(x). In some embodiments, the fluorinatedurethane oligomer of at least two repeat units comprises at least oneend group represented by the formula —O—(CH₂)_(n)N(R⁴)S(O)₂—Rf³, and atleast one end group represented by the formula —NH—(CH₂)_(n)—SiY₃,wherein Z, Rf², R⁴, Rf³, Y, and x are as defined above, and n is aninteger from 1 to 4.

The term “urethane oligomer” refers to oligomers containing at least oneof urethane or urea functional groups. In some embodiments, the at leastone fluorinated urethane oligomer of at least two repeat units comprisesthe reaction product of (a) at least one polyfunctional isocyanatecompound; (b) at least one polyol; (c) at least one fluorochemicalmonoalcohol; (d) at least one silane; and optionally (e) at least onewater-solubilizing compound comprising at least one water-solubilizinggroup and at least one isocyanate-reactive hydrogen containing group. Insome embodiments, at least one polyamine may also be used.

Useful fluorine urethane oligomers may be prepared, for example, byreaction of at least one polyfunctional isocyanate with at least onepolyol and reaction of the resulting oligomer with at least onefluorinated monoalcohol and at least one silane. Exemplary reactionconditions, polyfunctional isocyanates, polyols, fluorochemicalmonoalcohols, silanes, and water-solubilizing compounds are described inU.S. Pat. No. 6,646,088 (Fan et al.).

In some embodiments of formula —O—Z—Rf², Rf² is a monovalentperfluoroalkyl group described above for Rf in embodiments of a compoundof formula I.

The divalent organic linking group, Z, in formula —O—Z—Rf², can be alinear, branched, or cyclic structure, that may be saturated orunsaturated and optionally contains one or more heteroatoms selectedfrom the group consisting of sulfur, oxygen, and nitrogen, and/oroptionally contains one or more functional groups selected from thegroup consisting of ester, amide, sulfonamide, carbonyl, carbonate,ureylene, and carbamate. Z includes at least 1 carbon atom and not morethan about 25 carbon atoms (in some embodiments, not more than 24, 23,22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, or even not more than 10carbon atoms). In some embodiments of formulas II and IIa, Z is adivalent organic linking group as described above for divalent Q groups.In some embodiments of formulas II and IIa, Z is —C_(y)H_(2y)—,—CON(R¹)C_(y)H_(2y)—, —SO₂N(R¹)C_(y)H_(2y)—, or—C_(y)H_(2y)SO₂N(R¹)C_(y)H_(2y)—, wherein R¹ is hydrogen or alkyl of oneto four carbon atoms, and y is independently an integer from 1 to 6 (insome embodiments from 2 to 4). In some embodiments, Rf³ is aperfluoroalkyl group having from 2 to 5 (e.g., 4) carbon atoms. Anend-group of the formula —O—Z—Rf² ((in some embodiments,—O—(CH₂)_(n)N(R⁴)S(O)₂—Rf³) can be incorporated into a fluorinatedurethane oligomer by carrying out the condensation polymerizationreaction (e.g., as described above) in the presence of a fluorinatedmonoalcohol of formula HO—Z—Rf².

Useful fluorinated monoalcohols include, for example,2-(N-methylperfluorobutanesulfonamido)ethanol;2-(N-ethylperfluorobutanesulfonamido)ethanol;2-(N-methylperfluorobutanesulfonamido)propanol;N-methyl-N-(4-hydroxybutyl)perfluorohexanesulfonamide;1,1,2,2-tetrahydroperfluorooctanol; 1,1-dihydroperfluorooctanol;C₆F₁₃CF(CF₃)CO₂C₂H₄CH(CH₃)OH; n-C₆F₁₃CF(CF₃)CON(H)CH₂CH₂OH;C₄F₉OC₂F₄OCF₂CH₂OCH₂CH₂OH; C₃F₇CON(H)CH₂CH₂OH;1,1,2,2,3,3-hexahydroperfluorodecanol;C₃F₇O(CF(CF₃)CF₂O)₁₋₃₆CF(CF₃)CH₂OH; CF₃O(CF₂CF₂O)₁₋₃₆CF₂CH₂OH; andmixtures thereof. In some embodiments, the fluorinated monoalcohol isrepresented by the formula HO—(C_(n)H_(2n))N(R⁴)S(O)₂—Rf³.

An end-group of the formula —X¹—W—SiY_(3-x)(R)_(x) can be incorporatedinto a fluorinated urethane oligomer by carrying out the polymerizationreaction (e.g., as described above) in the presence of a silane offormula HX¹—W—SiY_(3-x)(R)_(x) (in some embodiments,H₂N—(CH₂)_(n)—SiY₃). Useful aminosilanes include, for example,H₂NCH₂CH₂CH₂Si(OC₂H₅)₃; H₂NCH₂CH₂CH₂Si(OCH₃)₃;H₂NCH₂CH₂CH₂Si(O—N═C(CH₃)(C₂H₅))₃; HSCH₂CH₂CH₂Si(OCH₃)₃;HO(C₂H₄O)₃C₂H₄N(CH₃)(CH₂)₃Si(OC₄H₉)₃; H₂NCH₂C₆H₄CH₂CH₂Si(OCH₃)₃;HSCH₂CH₂CH₂Si(OCOCH₃)₃; HN(CH₃)CH₂CH₂Si(OCH₃)₃; HSCH₂CH₂CH₂SiCH₃(OCH₃)₂;(H₃CO)₃SiCH₂CH₂CH₂NHCH₂CH₂CH₂Si(OCH₃)₃; HN(CH₃)C₃H₆Si(OCH₃)₃;CH₃CH₂OOCCH₂CH(COOCH₂CH₃)HNC₃H₆Si(OCH₂CH₃)₃; C₆H₅NHC₃H₆Si(OCH₃)₃;H₂C₃H₆SiCH₃(OCH₂CH₃)₂; HOCH(CH₃)CH₂OCONHC₃H₆Si(OCH₂CH₃)₃;(HOCH₂CH₂)₂NCH₂CH₂CH₂Si(OCH₂CH₃)₃; and mixtures thereof.

In some embodiments, the fluorinated silane comprises at least onereactive fluorinated silane, as described above, and a compound of theformula (V):

(R⁶)_(q)M(Y¹)_(p-q)  V,

wherein M represents an element of valency p+q selected from the groupconsisting of Si, Ti, Zr, B, Al, Ge, V, Pb, Sn and Zn (in someembodiments selected from the group consisting of Ti, Zr, Si and Al); R⁶represents a non-hydrolysable group (e.g., an alkyl group of 1 to 20carbon atoms which may be straight chained or branched and may includecyclic hydrocarbon structures, a C₆-C₃₀ aryl group, optionallysubstituted by one or more substituents selected from halogens and C₁-C₄alkyl groups, or a C₇-C₃₀ arylalkyl group); p is 3 or 4 depending on thevalence of M; q is 0, 1 or 2; and Y¹ represents a hydrolysable group(e.g., alkoxy, acyloxy, and halogen). Compounds of formula V andformulations containing compounds of formula V, fluorinated silanes, andoptionally other crosslinking agents are described, for example, in U.S.Pat. No. 6,716,534 (Moore et al.).

Representative examples of compounds of formula V includetetramethoxysilane, tetraethoxysilane, methyl triethoxysilane,dimethyldiethoxysilane, octadecyltriethoxysilane, methyltrichlorosilane, tetra-methyl orthotitanate, tetra ethyl orthotitanate,tetra-iso-propyl orthotitanate, tetra-n-propyl orthotitanate, tetraethylzirconate, tetra-iso-propyl zirconate tetra-n-propyl zirconate. Mixturesof compounds of formula V may also be used in the preparation offluorinated silanes.

Typically the fluorinated silane is dissolved or dispersed in adispersing medium (e.g., water and/or organic solvent (e.g., alcohols,ketones, esters, alkanes and/or fluorinated solvents (e.g.,hydrofluoroethers and/or perfluorinated carbons)) that is then appliedto at least one of the fracture or proppant (including in someembodiments, treating the proppant prior to injecting the proppants intothe fracture). The amount of liquid medium used should be sufficient toallow the solution or dispersion to generally evenly wet the fractureand/or proppant being treated. Typically, the concentration of thefluorinated silane in the solution/dispersion solvent is the range fromabout 5% to about 20% by weight, although amounts outside of this rangemay also be useful. Some formulations containing fluorinated silanes(e.g., of formula I) that may be useful are included in U.S. Pat. No.6,613,860 (Dams et al.). For proppant treated prior to injection intothe fracture, the proppant can be treated, for example, with thefluorinated silane solution/dispersion at temperatures in the range fromabout 25° C. to about 50° C., although temperatures outside of thisrange may also be useful. The treatment solution/dispersion can beapplied to the proppant prior to injection into the fracture usingtechniques known in the art for applying solutions/dispersions toparticles (e.g., mixing the solution/dispersion and proppant in a vessel(in some embodiments under reduced pressure) or spraying thesolutions/dispersions onto the proppant).

For treatment of the fracture and/or proppant present in the fracture,the treatment solution/dispersion can be applied using techniques knownin the art for injecting solutions/dispersions to fractured subterraneanformations (e.g., utilizing a coiled a coiled tubing unit (CTU) or thelike).

In some embodiments, it may be desirable for the treatment solution toinclude contain viscosity enhancing agents (e.g., polymericviscosifiers), electrolytes, corrosion inhibitors, scale inhibitors, andother such additives that are common to a fracturing fluid.

After application of the treatment solution/dispersion to the proppantprior to injection into the fracture, the liquid medium can be removedusing techniques known in the art (e.g., drying the particles in anoven). After application of the treatment solution/dispersion to theproppant present in the fracture and/or the fracture, the liquid mediumcan be removed using techniques known in the art (e.g., allowing thefracture to begin production of hydrocarbons). Typically, about 0.1 toabout 5 (in some embodiments, for example, about 0.5 to about 2) percentby weight fluorinated silane is added to the proppant and/or fracture,although amounts outside of this range may also be useful.

Hydrolysis of the Y groups (i.e., alkoxy, acyloxy, or halogen) ofreactive fluorinated silanes typically generates silanol groups, whichparticipate in condensation reactions to form fluorinated siloxanes, forexample, according to Scheme I, and/or participate in bondinginteractions with silanol groups or other metal hydroxide groups on thesurface of the proppant particles). The bonding interaction may bethrough a covalent bond (e.g., through a condensation reaction) orthrough hydrogen bonding. Hydrolysis can occur, for example, in thepresence of water optionally in the presence of an acid or base (in someembodiments, acid). The water necessary for hydrolysis made be added toa formulation containing the fluorinated silane that is used to coat theparticles (e.g., proppants), may be adsorbed to the surface of theparticles, or may be present in the atmosphere to which the fluorinatedsilane is exposed (e.g., an atmosphere having a relative humidity of atleast 10%, 20%, 30%, 40%, or even at least 50%). Water (e.g., brine) maybe present in a subterranean geological formation comprisinghydrocarbons and may cause hydrolysis of hydrolysable groups on afluorinated silane (and cause condensation to provide a fluorinatedsiloxane) during the injection of particles into a fracture of theformation. The water present in the subterranean geological formationmay be natural occurring water (e.g., connate water) or water from aman-made source (e.g., hydraulic fracturing or waterflooding).

Under neutral pH conditions, the condensation of silanol groups istypically carried out at elevated temperature (e.g., in a range from 40°C. to 200° C. or even 50° C. to 100° C.). Under acidic conditions, thecondensation of silanol groups may be carried out at room temperature(e.g., in a range from about 15° C. to about 30° C. or even 20° C. to25° C.). The rate of the condensation reaction is typically dependentupon temperature and the concentration of fluorinated silane (e.g., in aformulation containing the fluorinated silane).

Techniques for fracturing subterranean geological formation comprisinghydrocarbons are known in the art, as are techniques for injectingproppants into the fractured formation to prop open fracture openings.In some methods, a hydraulic fluid is injected into the subterraneangeological formation at rates and pressures sufficient to open afracture therein. The fracturing fluid (usually water with specialtyhigh viscosity fluid additives) when injected at the high pressuresexceeds the rock strength and opens a fracture in the rock. Proppant canbe included in the fracturing fluid.

An advantage, in some embodiments, of treated particles having aplurality of pores is that the treated particle has at least one ofwater or oil imbibition up to 95% as compared to a comparable, untreatedparticle. The water and oil absorption (i.e., water and oil imbibition)of treated proppant can be measured immersing about 10 grams of thetreated proppant in about 20 grams of deionized water or a tetradecanesolution (obtained from Sigma-Aldrich, St Louis, Mo.), respectively, forabout 1 hour. The water or oil, respectively, is then filtered off withfilter paper (Qualitative Grade 4); Whatman Filter Paper, Florham Park,N.J. The surface water or oil, respectively, is then carefully removedwith paper towel, and the proppant again weighed. The water or oil,respectively, absorption is then calculated based on the difference inweight before and after immersion in the water or oil, respectively. Thewater or oil absorption, respectively, is the average of twomeasurements.

Advantages and embodiments of this invention are further illustrated bythe following examples, but the particular materials and amounts thereofrecited in these examples, as well as other conditions and details,should not be construed to unduly limit this invention. All parts andpercentages are by weight unless otherwise indicated.

Prophetic Example

A fracture fluid comprising proppant (e.g., bauxite particles) isinjected into a well in a subterranean formation that produceshydrocarbons. The fracture fluid is injected at a pressure that is abovethe fracture pressure of the formation, resulting in a fracture andplacement of the proppant in the fracture zone. The fracturing fluid issubsequently produced once the well is opened for production. Next, amethanolic treatment solution containing 99 percent by weight methanoland 1 percent by weight of fluorinated silane is injected into thefracture. The treatment solution is injected into the fracture at apressure sufficient to wet substantially the entire fracture andproppant in the fracture, but not at a pressure high enough to introducenew fractures into the formation. The treatment remains in the proppantfilled fracture long enough for the silane to treat the fracture and theproppant (e.g., about 1 hour). The well is then put back on production,and the treatment fluid is produced, leaving behind the proppant andfluorinated siloxane.

Various modifications and alterations of this invention will becomeapparent to those skilled in the art without departing from the scopeand spirit of this invention, and it should be understood that thisinvention is not to be unduly limited to the illustrative embodimentsset forth herein.

1. (canceled)
 2. A method of treating proppant particles present in a fractured subterranean geological formation comprising hydrocarbons, the method comprising injecting fluorinated silane into the fracture to treat the proppant particles in-situ, wherein the fluorinated silane is selected from the group consisting of: Rf{-Q-[SiY_(3-x)(R)_(x)]_(y)}_(z); a polymeric fluorinated composition comprising: at least one divalent unit represented by the formula:

 and at least one of at least one divalent unit represented by the formula:

 or a chain-terminating group represented by the formula: —S—W—SiY_(3-x)(R)_(x); and a fluorinated urethane oligomer of at least two repeat units comprising: at least one end group represented by the formula —O—Z—Rf², and at least one end group represented by the formula —X¹—W—SiY_(3-x)(R)_(x); wherein Rf is a monovalent or multivalent perfluoropolyether group having two or more in-chain oxygen atoms; Rf² is a monovalent perfluoroalkyl group optionally interrupted by at least one —O—; each R is independently selected from the group consisting of alkyl having one to six carbon atoms and aryl; Q is a divalent or trivalent organic linking group; each Y is independently selected from the group consisting of hydroxyl, alkoxy, acyloxy, and halogen; each R¹ is independently selected from the group consisting of hydrogen and alkyl having one to four carbon atoms; each W is independently selected from the group consisting of alkylene, arylalkylene, and arylene, wherein alkylene is optionally interrupted by or substituted by at least one heteroatom; each X is independently selected from the group consisting of —NH—, —O—, and —S—; X¹ is selected from the group consisting of —N(H)—, —N(CH₃—, —N(C₆H₅)—, —S—, —O—, —O—C(O)—NH—, and —O-alkylene-O—C(O)—NH—; Z is a divalent organic linking group; x is 0, 1, or 2; y is 1 or 2; and z is 1, 2, 3, or
 4. 3. The method according to claim 2, wherein the fluorinated silane comprises at least one fluorinated urethane oligomer of at least two repeat units comprising: at least one end group represented by the formula —O—(CH₂)_(n)N(R⁴)S(O)₂—Rf³, and at least one end group represented by the formula —NH—(CH₂)_(n)—SiY₃; wherein R⁴ is alkyl having one to four carbon atoms; Rf³ is a perfluoroalkyl group having from one to eight carbon atoms; each Y is independently selected from the group consisting of hydroxyl, alkoxy, acyloxy, and halogen; and each n is independently an integer from 1 to
 4. 4. The method according to claim 2, wherein at least a portion of the proppant particles are ceramic particles.
 5. The method according to claim 2, wherein at least a portion of the proppant particles are engineered particles.
 6. The method according to claim 2, wherein at least a portion of the proppant particles are at least 500 micrometers in size.
 7. The method according to claim 2, wherein at least a portion of the treated proppant particles have a plurality of pores, and wherein at least a portion of the treated proppant particles have at least one of water or oil imbibition up to 95% as compared to comparable, untreated proppant particles.
 8. A method of fracturing a subterranean geological formation comprising hydrocarbons, the method comprising: injecting a hydraulic fluid into a subterranean geological formation comprising hydrocarbons at a rate and pressure sufficient to open a fracture therein; injecting into the fracture a fracture fluid comprising a plurality of proppant particles; and subsequent to the injection of the hydraulic and fracture fluids, injecting fluorinated silane into the fracture to treat the proppant particles in-situ, wherein the fluorinated silane is selected from the group consisting of: Rf{-Q-[SiY_(3-x)(R)_(x)]_(y)}_(z); a polymeric fluorinated composition comprising: at least one divalent unit represented by the formula:

 and at least one of at least one divalent unit represented by the formula:

 or a chain-terminating group represented by the formula: —S—W—SiY_(3-x)(R)_(x); and a fluorinated urethane oligomer of at least two repeat units comprising: at least one end group represented by the formula —O—Z—Rf², and at least one end group represented by the formula —X¹—W—SiY_(3-x)(R)_(x); wherein Rf is a monovalent or multivalent perfluoropolyether group having two or more in-chain oxygen atoms; Rf² is a monovalent perfluoroalkyl group optionally interrupted by at least one —O—; each R is independently selected from the group consisting of alkyl having one to six carbon atoms and aryl; Q is a divalent or trivalent organic linking group; each Y is independently selected from the group consisting of hydroxyl, alkoxy, acyloxy, and halogen; each R¹ is independently selected from the group consisting of hydrogen and alkyl having one to four carbon atoms; each W is independently selected from the group consisting of alkylene, arylalkylene, and arylene, wherein alkylene is optionally interrupted by or substituted by at least one heteroatom; each X is independently selected from the group consisting of —NH—, —O—, and —S—; X¹ is selected from the group consisting of —N(H)—, —N(CH₃)—, —N(C₆H₅)—, —S—, —O—, —O—C(O)—NH—, and —O-alkylene-O—C(O)—NH—; Z is a divalent organic linking group; x is 0, 1, or 2; y is 1 or 2; and z is 1, 2, 3, or
 4. 9. (canceled)
 10. The method according to claim 8, wherein the fluorinated silane comprises at least one fluorinated urethane oligomer of at least two repeat units comprising: at least one end group represented by the formula —O—(CH₂)_(n)N(R⁴)S(O)₂—Rf³, and at least one end group represented by the formula —NH—(CH₂)_(n)—SiY₃; wherein R⁴ is alkyl having one to four carbon atoms; Rf³ is a perfluoroalkyl group having from one to eight carbon atoms; each Y is independently selected from the group consisting of hydroxyl, alkoxy, acyloxy, and halogen; and each n is independently an integer from 1 to
 4. 11. The method according to claim 8, wherein at least a portion of the proppant particles are ceramic particles.
 12. The method according to claim 8, wherein at least a portion of the proppant particles are engineered particles.
 13. The method according to claim 8, wherein at least a portion of the proppant particles are at least 500 micrometers in size.
 14. The method according to claim 8, wherein at least a portion of the treated proppant particles have a plurality of pores, and wherein at least a portion of the treated proppant particles have at least one of water or oil imbibition up to 95% as compared to comparable, untreated proppant particles.
 15. A method of fracturing a subterranean geological formation comprising hydrocarbons, the method comprising: injecting a hydraulic fluid into a subterranean geological formation comprising hydrocarbons at a rate and pressure sufficient to open a fracture therein; injecting fluorinated silane into the fracture to treat the fracture in-situ, wherein the fluorinated silane is selected from the group consisting of: Rf{-Q-[SiY_(3-x)(R)_(x)]_(y)}_(z); a polymeric fluorinated composition comprising: at least one divalent unit represented by the formula:

 and at least one of at least one divalent unit represented by the formula:

 or a chain-terminating group represented by the formula: —S—W—SiY_(3-x)(R)_(x); and a fluorinated urethane oligomer of at least two repeat units comprising: at least one end group represented by the formula —O—Z—Rf², and at least one end group represented by the formula —X¹—W—SiY_(3-x)(R)_(x); wherein Rf is a monovalent or multivalent perfluoroalkyl group optionally interrupted by at least one —O—; Rf² is a monovalent perfluoroalkyl group optionally interrupted by at least one —O—; each R is independently selected from the group consisting of alkyl having one to six carbon atoms and aryl; Q is a divalent or trivalent organic linking group; each Y is independently selected from the group consisting of hydroxyl, alkoxy, acyloxy, and halogen; each R¹ is independently selected from the group consisting of hydrogen and alkyl having one to four carbon atoms; each W is independently selected from the group consisting of alkylene, arylalkylene, and arylene, wherein alkylene is optionally interrupted by or substituted by at least one heteroatom; each X is independently selected from the group consisting of —NH—, —O—, and —S—; X¹ is selected from the group consisting of —N(H)—, —N(CH₃—, —N(C₆H₅)—, —S—, —O—, —O—C(O)—NH—, and —O-alkylene-O—C(O)—NH—; Z is a divalent organic linking group; x is 0, 1, or 2; y is 1 or 2; and z is 1, 2, 3, or 4, and after injecting the fluorinated silane into the fracture, injecting a fracture fluid comprising a plurality of proppant particles into the fracture.
 16. The method according to claim 15, wherein prior to injecting the fluorinated silane into the fracture, the method further comprises injecting a fracture fluid comprising a plurality of proppant particles into the fracture.
 17. (canceled)
 18. The method according to claim 15, wherein at least some of the proppants injected into the fracture are treated with the fluorinated silane prior to their injection.
 19. The method according to claim 15, wherein the fluorinated silane comprises at least one fluorinated urethane oligomer of at least two repeat units comprising: at least one end group represented by the formula —O—(CH₂)_(n)N(R⁴)S(O)₂—Rf³, and at least one end group represented by the formula —NH—(CH₂)_(n)—SiY₃; wherein R⁴ is alkyl having one to four carbon atoms; Rf³ is a perfluoroalkyl group having from one to eight carbon atoms; each Y is independently selected from the group consisting of hydroxyl, alkoxy, acyloxy, and halogen; and each n is independently an integer from 1 to
 4. 20. The method according to claim 15, wherein the fracture has a conductivity improved by the presence of fluorinated siloxane which is a condensation product of the fluorinated silane. 